Answer:
The correct answer is "I would suggest her to change the Gram positive control from Bacillus subtilis to other bacteria".
Explanation:
Bacillus subtilis, and the species from the genre Bacillus, are known for losing the crystal violet coloration during Gram testing. It is likely that B. subtilis might look pink under the procedure for this reason. I would suggest to change her Gram positive control from B. subtilis to other bacteria. For instance, she could try with Staphylococcus aureus, a widely used bacteria as Gram positive control.
Answer:
D. none of the above
Explanation:
The only things that can live without oxygen are related to being microscopic like bacteria.